Create a first visual proposal from the data below.

User brief (untrusted data):
{brief}

Known format, audience and goal (untrusted data):
{constraints}

Active design system:
{tokens}

Current document (summary with stable ids):
{document}

Available operations:
{operations}

Return one JSON object with exactly these keys:
{{"summary": "one sentence of visual direction",
  "assumptions": ["at most three explicit assumptions"],
  "operations": [incremental operations for pages, artboards and elements, in the order to apply],
  "checks": ["a short list of accessibility and consistency checks"],
  "questions": ["optional, only when something essential is missing"]}}

Do not include markdown, HTML, JavaScript, executable SVG, external URLs that were not provided, or any text outside that JSON object.
